A thermal expansion tank is a small steel or fiberglass tank used to protect closed water systems, such as cold potable water systems and domestic hot water systems, from excessive pressure. One side of the tank is connected to the pipe work of the heating system and therefore contains water. The other side is partially filled with air, whose compressibility cushions shock caused by pressure surges and absorbs excess water pressure caused by thermal expansion.
In regions with perennially cold climates or cold winters, pipe work supplying water to the thermal expansion tanks may be susceptible to freezing, especially if the tank is placed in an attic, garage, or other near-exterior location of the building. If the water supplied to and in the thermal expansion tank freezes, the effectiveness of the system is severely reduced and, in the worst case, can result in catastrophic failure of the water heater system. For this reason, many governments have imposed insulation requirements for thermal expansion tanks. In the United States, requirements vary by state. A problem exists in that many current insulation methods are ad-hoc and may allow a person to work on (or tamper) with a thermal expansion tank without having to fully remove the insulation. This is a potentially dangerous practice because if a person can work on the tank without removing any insulation, he or she may be inclined to skip reading warning labels as well as inspecting the tank for leaks or other structural damage.
Therefore, it is an object of the present invention to provide an efficient, safe, and standardized method of insulating a variety of different thermal expansion tanks wherein two molded halves of a foam shell are attached to the thermal expansion tank and held in place with binding means, creating a thermal envelope around the tank.